Battery systems having a plurality of cells are used as energy storage devices in motor vehicles, by way of example for driving electric vehicles and hybrid vehicles.
A battery system of the generic type is known from German Patent Publication No. DE 11 2011 101 397 T5. A connecting structure for a wiring element is disclosed, wherein a soldered section is formed on an end section of a bus bar. A protruding part that is embodied in the form of a pin is formed in the soldered section. The protruding part is guided through a perforated section of the wiring element. The wiring element is formed by way of a flexible circuit board. The protruding part that is guided through the perforated section and a circuit pattern of the wiring element are soldered one to the other.
In the case of the known applications, a high level of automation when assembling the battery system is desired, as is a reliable electrical connection over the entire serviceable life between the cell connector and the electronic unit by way of the conductor. The voltage of the cells is directed by way of this electrical connection to the electronic unit for evaluations purposes. Furthermore, the electronic unit is frequently designed so as to purposefully reduce the charge state of the cells by way of a discharge process by way of a resistor that may be switched parallel to each cell, wherein the current circuit is directed by way of the conductor for this discharge process. An increase in the transition resistance between the electrical connection between the cell connector and the electronic unit would be directly included in the evaluation process as a measuring error, since an increased voltage would drop off at the increased transition resistance. This is particularly undesirable when using lithium ion cells since in the case of this type of cells the cell voltage changes only slightly in a significant range of the charge content. As a result of agitations and vibrations that occur during the operation of the motor vehicle, the transition resistance of a solder connection can increase or the solder connection can separate, which is also undesirable.